(ITS#6291) nssov getgroupbymembers is broken

Full_Name: Howard Chu
Version: 2.4.18/HEAD
OS: Linux
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (76.91.220.157)
Submitted by: hyc
The getgroupbymember nss function expects the list of groups to be terminated by
NSLCD_RESULT_END. The NSSOV_HANDLE macro is neglecting to write this result.
(Technically, every response is supposed to end with this code, but none of the
other nss functions try to read it, so this bug doesn't impact any of them.)